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This has been active in Stockholm for years, at least:

https://www.opendistrictheating.com/

Also Wedos here in Czech republic; https://www.wedos.org/en/

It's a bit hard when the temperature deltas are so small, though. It probably works well if you're pre-heating air before the main heat source in a very cold region, but otherwise you'd need to use some sort of heat pump to get it to move around.